epistasis

US: (i pis′tə sis)

WordReference Random House Unabridged Dictionary of American English © 2025

e•pis•ta•sis  (i pis′tə sis), n., pl. -ses 

(-sēz′). 
1. Genetics a form of interaction between nonallelic genes in which one combination of such genes has a dominant effect over other combinations.
2. Medicine
   • the stoppage of a secretion or discharge.
   • a scum that forms on a urine specimen upon standing.

• Greek epístasis stopping, stoppage. See epi-, stasis
• 1915–20;

ep•i•stat•ic  (ep′ə stat′ik), adj.